New Early Dark Energy as a solution to the $H_0$ and $S_8$ tensions

Abstract

New Early Dark Energy introduces a new phase of dark energy that decays in a fast-triggered phase transition around matter-radiation equality. The presence of a trigger mechanism sets it apart from other early dark energy models. Here, we will argue that New Early Dark Energy offers a simple and natural framework to extend $\Lambda$CDM while also providing a pathway to resolving the $H_0$ tension alongside its smaller cousin, the $S_8$ tension. At the microscopic level, we discuss the possibility that the trigger is either given by an ultralight scalar field or a dark sector temperature. In both cases, it prompts the transition of an $\mathrm{eV}$-mass scalar field from its false to its true minimum. Furthermore, we argue that the same phase transition could give rise to a dynamic process for generating neutrino masses.

Invited chapter for the edited book Hubble Constant Tension (Eds. E. Di Valentino and D. Brout, Springer Singapore, expected in 2024)

References in corpus (14)

• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• The James Webb Space Telescope
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• The Swampland: Introduction and Review
• The NANOGrav 15-year Data Set: Search for Signals from New Physics
• The $H_0$ Olympics: A fair ranking of proposed models
• Consistency tests of $\Lambda$CDM from the early integrated Sachs-Wolfe effect: Implications for early-time new physics and the Hubble tension
• New constraint on Early Dark Energy from Planck and BOSS data using the profile likelihood
• Dark Energy at early times and ACT: a larger Hubble constant without late-time priors
• Hints of Early Dark Energy in Planck, SPT, and ACT data: new physics or systematics?
• Hot New Early Dark Energy
• Chain Early Dark Energy: Solving the Hubble Tension and Explaining Today's Dark Energy
• Hot New Early Dark Energy: Towards a Unified Dark Sector of Neutrinos, Dark Energy and Dark Matter
• A grounded perspective on New Early Dark Energy using ACT, SPT, and BICEP/Keck

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• Linear matter density perturbations in the ${\Lambda }_{\mathrm{s}}$CDM model: Examining growth dynamics and addressing the $S_8$ tension
• Do we need wavelets in the late Universe?
• Beyond LambdaCDM: How the Hubble tension challenges early universe physics
• Quintessence and false vacuum: Two sides of the same coin?
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